This invention relates to removal of impurities from metal working coolant and the like. More particularly, this invention relates to a centrifuge system for removing such impurities.
Coolant must be cleaned and purified to remove metal chips and fines and to remove tramp oils.
Coolant purifying systems are known in which a filtration system removes gross solids and in which tramp oil is separated in a centrifuge such as the Alfa-Laval centrifuge WSPX-204. In this type of centrifuge, clean coolant and tramp oil are separated by reason of differing specific gravities and are pumped from the centrifuge. Solids collect in an outer portion of a bowl assembly of the centrifuge and, at predetermined intervals, allowed to "shoot" or vacate the bowl assembly automatically. The shoot is accomplished in a split second opening of the bowl assembly while the centrifuge is running. Power for causing the opening of the bowl assembly is secured from operating liquid which is introduced under pressure through an operating liquid opening of the centrifuge. The operating liquid can be outside water, which passes into the centrifuge and is discharged from the centrifuge with centrifuged coolant. Mixing of the outside water with the centrifuged coolant introduces impurities into the coolant from the outside water. An object of this invention is to provide a coolant cleaning system which does not introduce impurities from outside liquid into the coolant cleaning system.
A further object of this invention is to provide a coolant purifying system in which clean coolant from the centrifuge is used as the operating liquid so that there is no introduction of outside liquid.